Super large capacity virtual magnetic disk storage system

The present invention relates to a super-large-capacity virtual magnetic disk storage system, belonging to the field of computer storage technology. Said invention utilizes SCSI bus or network communication link to make communication with open system main machine. It includes virtual magnetic disk server and magnetic tape library, the described virtual magnetic disk server includes miniature computer system interface adapter, processor, magnetic disk array and memory; said memory includes address mapping module, command conversion module, writing module, buffer memory management module, reading prefetching module, virtual storage module and buffer storage module; the magnetic tape library includes medium exchange unit, magnetic tape driver unit and storage unit. Between the virtual magnetic disk server and magnetic tape library they are connected by means of SCSI bus.